Several different types of oil-in-water or water-in-oil emulsions are known in the art and have various uses. Such emulsions are sometimes used in enhanced oil recovery operations as a drive or pusher fluid to displace the hydrocarbons to a producing well. To be effective, the drive fluid preferably has a viscosity that is about 2 to 3 times the viscosity of the oil being displaced. A benefit of using a water-in-oil emulsion as a drive fluid is that it can be made with readily available materials in a relatively inexpensive manner. However, a 60/40 water-in-oil emulsion (60% water dispersed within 40% oil phase) will exhibit a viscosity in a range that is about 20 to 30 times that of the oil, which is higher than the desired mobility ratio for a drive fluid. Accordingly, there is a need in the industry for an economically affordable fluid with satisfactory viscosity and stability characteristics for use as an enhanced oil recovery drive fluid.
Oil-in-water and water-in-oil emulsions have also been used in lubrication applications. However, the main drawback of an emulsion lubricant is its instability to shear and its shear-thinning characteristics. Lubrication applications involve contact between moving surfaces, and emulsion instability due to shear will result in emulsion break-up and subsequent loss of ability to function as a lubricant. Accordingly, an emulsion is needed that has improved stability to shear and reduced shear-thinning for use in lubrication applications.